The invention relates to apparatus for severing running webs of paper or the like, and more particularly to improvements in apparatus which can be utilized to sever running webs of tipping paper or the like in tobacco processing machines, especially in filter tipping machines wherein plain cigarettes and filter plugs are assembled into filter cigarettes of unit length or multiple unit length. Certain machines of such type are known as MAX and MAX S (distributed by the assignee of the present application). Reference may be had, for example, to commonly owned U.S. Pat. No. 4,177,670 to Heitmann et al. which discloses a filter tipping machine wherein pairs of plain cigarettes are connected with filter mouthpieces of multiple unit length by rolling therearound adhesive-coated uniting bands which are obtained in response to repeated severing of the leader of a running web of tipping paper consisting of cigarette paper, imitation cork or other suitable flexible strip material.
Commonly owned U.S. Pat. No. 4,503,867 to Barbe et al. discloses an apparatus which is designed to sever a running web of tipping paper and wherein the cutting edges of a set of knives on a rotary knife carrier cooperate with a rotary drum-shaped counterknife to sever the running web of tipping paper at regular intervals. The web is trained over and is advanced by the peripheral surface of the counterknife, and its leader is severed whenever the cutting edge of a knife reaches the nip of the counterknife and the drum-shaped knife carrier. The apparatus of Barbe et al. includes individual adjusting means for each knife and a common adjusting device for all of the knives. Individual adjusting means are desirable for initial adjustment of a new knife or a reinserted knife. The common adjusting device is used to simultaneously compensate for wear upon all of the knives, for example, after each shift. Each knife is tiltable in its carrier and has at least some freedom of movement relative to the carrier and relative to the counterknife during each stage of operation of the patented apparatus.
A different apparatus for severing running webs of tipping paper is disclosed in commonly owned U.S. Pat. No. 3,340,757 to Rudszinat. The apparatus of Rudszinat is designed in such a way that each adjustment of the knives with reference to their carrier necessitates removal of the carrier from the filter tipping machine and installation of the removed carrier in a specially designed device (shown in FIG. 8 of the patent) serving to ensure accurate positioning of each tiltably mounted knife prior to reinsertion of the carrier into the filter tipping machine. Tiltable mounting of knives in their carrier was considered desirable and advantageous because the cutting edge of each knife can find its way into full contact with the peripheral surface of the counterknife as a result of pivoting of the knife with reference to the carrier. This renders it necessary to mount the knives in such a way that they have at least some freedom of movement relative to their carrier, even when the apparatus is in actual use. Knives which are free to pivot relative to the carrier will strike against the counterknife with a force which is proportional to the action of centrifugal force (i.e., proportional to the RPM of the carrier) so that the peripheral surface of the counterknife and the cutting edges of the knives are subject to extensive wear, especially in a modern filter tipping machine which is designed to turn out many thousands of rod-shaped articles per minute.